PNW - Any more conifers croaking from borers than usual ??

[M.D. Vaden]

Anything out of the ordinary this year with borers in evergreens?

Just removed a dead Port Orford cedar for someone yesterday, and thought it was probably Phytophthora. As soon as I cut some limbs away, it was evident that borers infested it.

Last spring, I planted 2 Hinoki Cypress at one small project in a west Portland suburb. Two weeks later, I noticed one turning gold. Looked inside the canopy and could see the fine dust and holes above many of the limbs. Won't say which nursery I bought them from, but when I went back, there were upwards of 2 dozen Hinoki's in a few rows with the same problem. They went ahead and gave me a replacement no-charge.

Anyhow, I haven't seen any borer damage on evergreens in the past few years, but lately, twice in just a few months.

 

[newbym]

Up here on the coast I'm seeing turpentine beetles hitting one out of every two shore pines. I think it has a lot to do with how many trees went down in the Dec '06 storm and didn't get cleaned up -> lot's of breeding ground. I'd say it's going to be an epidemic next year when another generation or two is feeding.

Do you have any experience with Lindane? I read that it is effective for ~3 mos as a preventative measure when sprayed on the trunks... It's pretty nasty stuff from what I can find, but we've got a few specimen trees that I'm worried about preserving.

 

[M.D. Vaden]

Do you have any experience with Lindane? I read that it is effective for ~3 mos as a preventative measure when sprayed on the trunks... It's pretty nasty stuff from what I can find, but we've got a few specimen trees that I'm worried about preserving.

Used to know pesticides inside and out. Had a consultant license and commerical applicator license too. Then got burned-out on keeping up with the chemical stuff and let the licenses lapse about 12 years ago.

My knowledge of a lot of that stuff has gone to mush now.

Pretty much refer the pesticide stuff to others.

 

[bighugetrees]

More in Edmonds

Just removed 4 in Edmonds Washington with the same bore holes. Local arborist thought the trees were crowded and in too much shade? Possibly more subject to attack because of this.

Should trees be disposed of differently because of this?

 

[BRCCArborist]

I didnt know Lindane was still available. Most people use Onyx for Borers, which is a pretty high concentration of Bifenthrin.

 

[M.D. Vaden]

One more thing about the site where this tree died, is that black plastic is laid over most of the yard. There are plenty of other trees in the yard.

I suggested to the homeowner that he contact the local temp labor place and get workers out for a couple of days to lift the plastic and smooth the bark again.

 

[newbym]

As far as disposal of the material, I've always tried to burn the stuff if it's possible to make sure that I'm eliminating any egg galleries or adult beetles that might be in the wood still. Barring that, if you have the space, you can chip, then dump the chips in a sunny area and tarp the pile. Make sure that you create a positive seal around the edge of the tarp so nothing can get out, and the sun will everything in there. Depending on the amount of direct sunlight, leave the chips there for 2-4 weeks. Whatever you do, don't just leave piles of the slash around other pine trees, there have been a number of studies linking this to larger outbreaks of the beetles.

 

[bighugetrees]

for sure

Good idea on the burn and keep a chip pile covered in full sun. I was thinking there had to be something along these lines to help stop/reduce spread.

Great information.

Dan